The field of invention relates to mechanical packaging for electronic systems, generally; and, more specifically, to a keyed bumper device for electronic card and/or backplane protection.
An electronic system is an interworking group of electric xe2x80x9ccardsxe2x80x9d (also referred to as xe2x80x9cbladesxe2x80x9d, xe2x80x9cPC boardsxe2x80x9d and the like). Each card typically has a plurality of semiconductor chips that, together, perform functions directed to the overall functionality of the card. For example, in the case of a networking electronic system, a Line Interface Card (LIC) is typically responsible for receiving streams of information over a copper or fiber optic cable and then converting these streams of information into a data format that is usable by another, xe2x80x9cSwitchingxe2x80x9d and/or xe2x80x9cRoutingxe2x80x9d card. Switching and/or Routing cards are generally responsible for identifying, for each received stream of traffic, another LIC (a xe2x80x9ctransmittingxe2x80x9d LIC) that is appropriate for directing the traffic stream over an outbound copper or fiber optic cable.
The Switching and/or Routing card then directs each stream to its appropriate transmitting LIC. In this manner, incoming traffic streams are converted into outgoing traffic streams; and, as a consequence of the overall process, streams of traffic are directed to their proper destination. In order to assemble the electronic system into a cohesive whole, each card (e.g., the receiving LIC, the Switching and/or Routing card, and the transmitting LIC) xe2x80x9cplugs intoxe2x80x9d a backplane unit. The backplane unit (hereinafter, xe2x80x9cbackplanexe2x80x9d) serves as a medium for transporting the various traffic streams between different cards; and, typically, provides some form of mechanical stability for the cards themselves. FIG. 1 shows a depiction of a mechanical package for an electronic system.
The mechanical package typically includes a box-like structure 100 having a front panel 100a with openings 102, 103, 104 where cards are inserted. The backplane 101 is usually placed within the box-like structure 100 opposite and facing the front panel 100a. From the embodiment of FIG. 1, note that ten different cards can be inserted into the mechanical package. That is, a card can be introduced to the electronic system by inserting it through the front panel 100 and sliding it along one of tracks 110 through 119. Each track 110 through 119 therefore corresponds to a different xe2x80x9ccard slotxe2x80x9d into which a card can be inserted. When a card that is being inserted into a card slot reaches the back of the box 100 so as to meet the backplane 101, one or more connectors that are affixed to the card should line up and properly mate to one or more corresponding connectors that are affixed to the back plane.
Each of the connectors (whether on a card or on the backplane 101) typically contains a plurality of electronic connection units (e.g., pins and/or sockets) so that electrical signals can be properly transferred between the card and the backplane. FIG. 1 shows an embodiment of the backplane connectors for each of the ten card slots that tracks 110 through 119 correspond to. For example the backplane connectors for card slot 106 correspond to connectors 126,127,128; and, the backplane connectors for card slot 108 correspond to connectors 131 and 134. Note that the collection of backplane connectors for card slots 106 and 107 are different than the collection of backplane connectors for the remaining card slots in the electronic system.
Different card connector patterns as between different card slots may naturally arise when certain card slots are reserved for certain types of cards. For example, with respect to the embodiment of FIG. 1, card slots 106 and 107 may be reserved for Switching and/or Routing cards while the remaining card slots (that correspond to tracks 110-113 and 116-119) may be reserved for LIC cards. Here, given that the Switching and/or Routing cards perform a different function than that performed by the LIC cards, the design of each type of card may drive a different footprint to the backplane 100. As such, the design and manufacture of the backplane 100 will include card slots 106,107 reserved for the Switching and/or Routing cards that are different (with respect to the footprint pattern and/or the types of connectors employed) than those reserved for the LIC cards.